1. Field of the Invention
This invention relates to computer systems, and more particularly, to mechanisms to ensure reliability, serviceability, and availability.
2. Description of the Related Art
Many computer systems utilize various forms of read-only memory (ROM) in order to store critical system information. Such ROMs may include EEPROMs (electrically erasable/programmable ROM), SEEPROMs (serial EEPROM) and a wide variety of other read only memory types. The system PROM may store such information such as serial numbers, unit ID, part number, date of manufacture, current time and temperature, unit history, engineering change order data, and so forth. This information may be especially useful in field replaceable units (FRU's) in computer systems designed for high-availability (e.g. file servers). The data in these system PROMs may be useful in quickly diagnosing problems, or determining if an FRU must be replaced in order to ensure system reliability.
In many cases, a system PROM may be divided into a static section and a dynamic section. The dynamic section of ROM may be used to store information such as power, temperature, test histories, and so forth. The static section of the ROM may be used to store information including the part number, the serial number, and may also store information that is required in order to boot the computer system.
During system operation, it is possible for the system PROM to become corrupted. This can be especially troublesome when the static area of the ROM becomes corrupted, since information required for booting the computer system may be stored there. A corrupted system PROM may prevent a computer system from booting up. Since the computer system is unbootable at that point, it may be difficult to isolate the problem, since the failure of other system components may also cause a boot failure. Thus, it may be possible to incur a significant amount of time and expense in order to solve a problem that is simply based on a corrupted system PROM.